The first sequel took things from bad to worse. The second brings them back to merely bad. So, yes, for those seeking signs of improvement, they exist.

But no one should mistake this for a ringing endorsement of any kind.

It’s the sorry second sequel, Transformers: Dark of the Moon. And it’s essentially more of the same: robots colliding, triggering the who-cares response right on cue.

Once again, it’s good robots versus bad robots. Once again, it’s full of sound and fury, signifying nothing. And once again, unless you can think of nothing more entertaining than watching stuff blow up, it’s a collective sleeping pill.

Shia LaBeouf returns in this toy-inspired franchise as Sam Witwicky, who has saved the world twice already. Warring, shape-shifting robots from outer space are now residents of our planet, and we humans are headed for collateral-damage status. That means that Sam is headed for the hat trick.

His job hunt unsuccessful of late, Sam also feels nervous that his new girlfriend, Carly, played by model Rosie Huntington-Whitely, is getting involved with her boss, played by Patrick Dempsey. And she’ll soon be in mortal danger during the ongoing war between shape-shifting robots.

This time the evil Decepticons are targeting Chicago, where Sam and Major Lennox, played by Josh Duhamel, hope to aid the Autobots in doing battle against their enemies.

All this after a vaguely interesting opening: when Autobot leader Sentinel Prime attempts to launch the Ark, a Cybertronian spacecraft containing crucial technology from their planet, it crashes on the Earth’s moon in 1961, just as President John F. Kennedy is making his promise to the nation to put a man on the moon.

And the search for the Ark — and the race to get there first — is on.

Yep, it’s parallel history time: the reason for the space race and that moon landing that we so vividly remember has been, well, transformed.

But after teasing us with an intriguing springboard that gives us hope for a narrative we actually care about, inept storyteller Michael Bay quickly turns back into the demolition derby director he so cherishes being.

Bay (Bad Boys, The Rock, Armageddon, Pearl Harbor), working from Ehren Kruger’s screenplay, is back at the helm of his third Transformers outing to complete the proposed trilogy (following 2007’s Transformers and 2009’s Transformers: Revenge of the Fallen), literally toying with us again by adding a few new robots to the cast, and having newcomers Dempsey, John Malkovich, and Frances McDormand join returnees Tyrese Gibson and John Turturro among the live actioners, while first-timer voice-lender Leonard Nimoy joins returning voiceover artists Peter Cullen and Hugo Weaving.

As before, the pyrotechnics, some of it admittedly impressive but ultimately inconsequential, are all that matters, but there’s no meaningful context offered and no dramatic interest generated whatsoever. The machines upstage the humans, as expected, and everybody overacts (although who can blame them?) in this hyperactive, bombastic, mindless collection of edited-into-coleslaw action set pieces.

Excessive destruction: that’s what Bay seems to live for. When he tries to be sentimental or sincere or patriotic or, even worse, funny, it is simply cringeworthy to sit through.

But he’ll sure sell a lot of toys.

It also remains difficult to watch this kind of big-budget product, with the endless and pointless waste-laying climax in downtown Chicago, without wondering what might have been if all this time and money and talent and energy and all these resources had been devoted to material actually worth watching.

Oh, and Bay delivers this glorified toy commercial, the longest installment yet, at a running time of 154 minutes. For this.Really? Really.

So we’ll robotocize 2 stars out of 4 for another overblown robocalypse-now thriller, Transformers: Dark of the Moon. Ah, yes: over two-and-a-half hours of pure Bayhem. The third time’s the charmless.